diff --git a/cake/libs/view/helpers/prototype_engine.php b/cake/libs/view/helpers/prototype_engine.php
index 8840f52a0..eefd4b4bf 100644
--- a/cake/libs/view/helpers/prototype_engine.php
+++ b/cake/libs/view/helpers/prototype_engine.php
@@ -211,7 +211,7 @@ class PrototypeEngineHelper extends JsBaseEngineHelper {
 			break;
 			case 'slideIn':
 			case 'slideOut':
-				$name = ($name == 'slideIn') ? 'slideDown' : 'slideUp';
+				$name = ($name == 'slideIn') ? 'SlideDown' : 'SlideUp';
 				$effect = 'Effect.' . $name . '(' . $this->selection . $optionString . ');';
 			break;
 			case 'fadeIn':
diff --git a/cake/tests/cases/libs/view/helpers/prototype_engine.test.php b/cake/tests/cases/libs/view/helpers/prototype_engine.test.php
index 24fc5ff18..479b55f83 100644
--- a/cake/tests/cases/libs/view/helpers/prototype_engine.test.php
+++ b/cake/tests/cases/libs/view/helpers/prototype_engine.test.php
@@ -153,19 +153,19 @@ class PrototypeEngineHelperTestCase extends CakeTestCase {
 		$this->assertEqual($result, $expected);
 
 		$result = $this->Proto->effect('slideIn');
-		$expected = 'Effect.slideDown($("foo"));';
+		$expected = 'Effect.SlideDown($("foo"));';
 		$this->assertEqual($result, $expected);
 
 		$result = $this->Proto->effect('slideOut');
-		$expected = 'Effect.slideUp($("foo"));';
+		$expected = 'Effect.SlideUp($("foo"));';
 		$this->assertEqual($result, $expected);
 
 		$result = $this->Proto->effect('slideOut', array('speed' => 'fast'));
-		$expected = 'Effect.slideUp($("foo"), {duration:0.50000000000});';
+		$expected = 'Effect.SlideUp($("foo"), {duration:0.50000000000});';
 		$this->assertEqual($result, $expected);
 
 		$result = $this->Proto->effect('slideOut', array('speed' => 'slow'));
-		$expected = 'Effect.slideUp($("foo"), {duration:2});';
+		$expected = 'Effect.SlideUp($("foo"), {duration:2});';
 		$this->assertEqual($result, $expected);
 	}